Asphalt blends of hydrocarbon precipitated asphalts with hydrocarbon aromatic extracts



United States Patent t 3 476 679 ASPHALT BLENDS 01 HtIDROCARBON PRECIPI- TATED ASPHALTS WITH HYDROCARBON ARO- MATIC EXTRACTS 3,476,679 Patented Nov. 4, 1969 As can be readily seen, for all three penetration grades between 200-350 penetration, the vacuum-reduced asphalt does not meet specific gravity specifications of greater than 1 and the 250-300 and 300-350 penetration grades Eugene M- Fauher, Hammond, Ind" assign to Sinclair 5 do not meet ductility specifications of greater than 100. Research, 6-, New York, NY, a corporation of Thus there is a need for an improved asphalt in the 200- l 350 penetration range which meets the required specifi- No Drawing. Filed Aug. 19, 1966, Ser. No. 573,495 cations listed above.

Int. Cl. Cc 3/08; C10g 21/02 In order to obtain a feedstock for the process of the 208-45 8 Claims 10 present invention Mid-Continent crude can be first processed in a conventional crude still to remove the light ends and provide reduced crude bottoms. The reduced ABSTRACT OF THE DISCLOSURE crude bottoms can then be fed to a vacuum still to re- Asphalts of about 200-350 penetration at 77 F. having move the gas oil as overhead product and to produce as improved specific gravity and ductility properties and a toms, a product which has a viscosity of about 800 to method for producing such asphalts are disclosed. The as- 1500 SSU at 210 F., preferably about 1300 to 1500 SSU phalts contain about 70 to 85 weight percent of a hydroat 210 F., and which represents a substantial but minor carbon precipitated asphalt having a penetration at 77 part of the total crude, say for example about 10 to 3 F. of about 30-65, and about 15 to 30 weight percent of volume percent. a hydrocarbon aromatic extract having a gravity of about This bottoms product is next deasphalted by solvent 18 to 20 API. These components are derived from Midextraction using a hydrocarbon which is well known in Continent crude bottoms having a viscosity of about 800 the deasphalting art and often containing from about 3 to to 1500 SSU at 210 F. 5 carbon atoms such as, for example, propane, butane,

pentane, and mixtures thereof, with propane being the preferred solvent. The amount of solvent employed in This invention relates to improved asphalts and to a h deespbeuttug step may often Vary Within solvent to process f producing high grade asphalts Which can he oil weight ratio range of about 2 to 10:1. Particularly deused for instance, for paving roads. More particularly, slrahle ratloshre ahout 3 to 4 Volumes of solvent P this invention concerns a new method for processing Mid- Volume of Tesldual 011 g Continent crude to meet particular specifications of high The temperature at f e the deasphalhhg Step can quality asphalt. be c onducted may be within the range of about 110 to Asphalts of various types can be produced by the dis- 190 Pa Preterahuf about 120 to 165 There m be tillafion of crude n For example, a crude oil can be atemperature gradient in the deasphalting tower with the distilled, preferably under a vacuum, to produce a dark hlghest temperature f f deasphalted 011 Outlet- The residuum, i.e., one from which lubricating oil has been temperature gridleut wlthul the tower h range from removed. The residiuum can then be treated with solvents about 0 to 60 Tbus It may be desuabte to Control selective for the hydrocarbon oils and the dissolved and the temperature at the toP o the extraeuou tower at Say undissolved fractions can be separated by settlement and for example about 1604065 and at the bottom oh the decantation or if preferred by the use of a centrifuge. The tower at about 120440 Tueee opetatmg eohu1t1oh5 dissolved fraction can be used as a high grade asphalt often P deasphalted 011$ Yvlth a Vlscoslty of stock to be converted in the usual manner and the undisabout 150 to 250 U at 210 t I preferred to consolved fraction is a suitable stock for the production of a trol. e process to e deasphalted gas 011s E different type of asphalt of a lower quality than that repbostty the range about 185-193 SSU h 21o Wltb resented by the dissolved fraction, but which i particuvtseostty of about 190 SSU at betbg Partteularty lady useful for certain applications desirable. The deasphalted gasoil is taken off at the top The requirements and Specifications placed on asphalts of extraction tower generally in yields of at least about will vary depending upon their particular use and the by Volume on the atboubt of feed Introduced conditions to which they are exposed. For example, when Into the extractton mm and as h1g1} as about by considering paving asphalts for roads the demands placed 50 u b even blgber although a 35 to upon the asphalt will Vary depending upon the climatic s desirable. The hydrocarbon precipitated asphalt which conditions which the asphalt must tolerate. Thus in colder 1S fb the bottom of e tower may have climates the required specifications for paving asphalts penetration at 77 F. of about 30-65, however, a product will differ from those in warmer climates having a penetration of about 45-65 is preferred.

This invention comprises a novel process f manu- The deasphalted gas oil recovered as overhead from the facturing asphalt with grades between about 200-350 y h @{XtFaCUOH 1S fed 10 a v na penetration at 77 F., to meet specific asphalt requirearomatic selective solvent treating plant or extraction unit. ments which cannot be met with conventional methods Due to the relatively low aromatic nt f the feed of manufacture, when processing Mid-Continent petromaterial 9 the iffiatlng Plant, a relatively Small Volume leum crude oils. The required specifications which must afoljnatlc Solvent can be employed- The solvent to h be met by the asphalt Produced by the process of h 011 ratio and tower temperatures are controlled to yield present invention are shown in Table I, and are compared tWO Products after the removal of the Solvent Whlch with vacuum reduced asphalt prepared from Mid-Contiis less soluble in the solvent, known as raffinate, and the nent crude by conventional methods of manufacture. other, which is more soluble in the solvent, known as ex- TABLE I Vacuum-Reduced Asphalt Tests Required Specifications from Mid-Continent Crude Stitttttihfitatttg:Pitt: t e? i 3 3 263 tract. In achieving these products the solvent to gas oil feed ratio can vary widely, often from about 1:1 to 6:1, more preferably about 2:1 to 4:1. The temperature at which the solvent treating step can be conducted may be in the range of about 150 to 230 F., preferably about 170 to 210 F.

While phenol is generally used as the aromatics extraction solvent, other solvents such as furfural, su fur dioxide, 2-2-dichloro diethyl ether, nitrobenzene, etc. can also be employed. The API gravity of the solvent-free rafiinate can vary, for instance be in a range of about 15 to 35; however, for preferred operations, the rafiinate has a gravity of about 25 to 30 API, say about 27 API, and the gravity of the solvent-free extract may often vary from about 18 to 20 API. The yield of rafiinate may be greater than 40% by volume based on the amount of deasphalted gas oil feed introduced into the aromatic solvent extraction unit, preferably the yield is about 50-60 percent by volume.

A precipitated asphalt recovered from the hydrocarbon deasphalting unit previously discussed is blended with an extract recovered from the aromatic solvent extraction unit to give an asphalt blend which meets the asphalt specifications as previously set out. Thus these two fractions can be blended to meet specific gravity and ductility specifications for penetration grades between 200-250, 250-300, and 300-350. The amount of hydrocarbon precipitated asphalt in the asphalt/extract blend may vary depending upon the penetration range or grade of asphalt desired in the final product. Generally about 70 to 85 weight percent precipitated asphalt can be used with the preferred amount depending upon the grade of asphalt to be produced. The extract is then usually about 15 to 30 weight percent of the blend. In any event the blend has a specific gravity greater than 1.

The following table lists the properties of a hydrcar bon precipitated asphalt and an aromatic extract of this invention and shows two typical blends, both of which meet the desired paving asphalt specifications.

D API Gravity Stocks:

Propane Precipitated Asphalt, Wt.

Percent 75 Extract, Wt. Percent 2O 25 Total, Wt. Percent 100 Laboratory Tests:

Penetration at 77 F 211 305 Ductility at 77 F +151 +151 Specific Gravity, 77/77 FL. 1. 0031 1.000 Oliensis Spot Negative Negative Flash, CO C, F 605 60 The propane precipitated asphalt of Table II can be made from a reduced crude having a viscosity of 1410 SSU at 210 F. In the propane extraction the solvent to oil volume ratio is 4:1 and the tower temperatures are 160 F. at the top and F. at the bottom. The yield of deasphalted oil is 37 volume percent and the yield of asphalt is 63 volume percent and the asphalt has characteristics essentially as set forth in Table II. The deasphalted oil has a viscosity of 190 SSU at 210 F. and is phenol extracted at a solvent to oil volume ratio of 3 :1 in a tower having a temperature of 210 F. at the top and 205 F. at the bottom. Tests on the resulting solventfree extract are essentially those given in Table II.

Thus, by using the processing method of the present invention, paving asphalt which meets desired specifications can be made from Mid-Continent crude which could not otherwise be done when processing Mid-Continent crude by conventional methods of manufacture. Although the present invention for producing a high grade asphalt is discussed in terms of one integrated process, the hydrocarbon precipitated asphalt and the extract components which are blended together to produce the desired asphalt product need not be derived from the same reduced crude.

It is claimed:

1. A process for making asphalt which comprises deasphalting Mid-Continent crude bottoms having a viscosity of about 800-1500 SSU at 210 F. by contact with a C to C hydrocarbon solvent at a temperature of about 110-190 F. to produce a deasphalted gas oil and a hydrocarbon precipitated asphalt having a penetration at 77 F. of about 30-65, extracting said deasphalted gas oil with a solvent selective for aromatics from the group consisting of phenol, furfural, sulfur dioxide, 2,2-dichlorodiethyl ether, and nitrobenzene, at a temperature of about -230 F. to form a raffinate and an aromatic extract having a gravity of about 18-20 API, and blending about 15 to 30 percent by weight of said aromatic extract with about 70-85 percent by Weight of said hydrocarbon precipitated asphalt to produce an asphalt product having a penetration range at 77 F. of about 200- 350, a specific gravity, 77/77 F. of greater than one, and a ductility at 77 F. greater than 100 cm.

2. The process of claim 1 in which the deasphalting hydrocarbon solvent is propane.

3. The process of claim 1 in which the aromatic solvent is phenol.

4. The process of claim 1 in which the deasphalting hydrocarbon solvent is propane and the solvent selective for aromatics is phenol.

5. A process for making asphalt having a penetration at 77 F. of about 200-350, a specific gravity, 77/77 F. of greater than one, and a ductility at 77 F. greater than 100 cm. which comprises deasphalting Mid-Continent crude bottoms having a viscosity of about 1300- 1500 SSU at 210 F., by contact with a C to C hydrocarbon solvent at a temperature of about 120165 F. to produce a deasphalted gas oil having a viscosity of about to SSU at 210 F., and a hydrocarbon precipitated asphalt having a penetration at 77 F. of about 45-65, extracting said deasphalted gas oil with a solvent selective for aromatics from the group consisting of phenol, furfural, sulfur dioxide, 2,2-dichlorodiethyl ether, and nitrobenzene, at a temperature of about 150 to 230 F. to form a raffinate and an aromatic extract with a gravity of about 18-20 API, and blending about 15 to 30 percent by weight of said aromatic extract with about 70-85 percent by weight of said hydrocarbon precipitated asphalt to produce the said asphalt product.

6. The process of claim 5 in which the deasphalting hydrocarbon solvent is propane.

7. The process of claim 5 in which the solvent selective for aromatics is phenol.

8. The process of claim 5 in which the deasphalting hydrocarbon solvent is propane and the solvent selective for aromatics is phenol.

References Cited UNITED STATES PATENTS 2,010,423 8/1935 Wells 208-23 2,073,088 3/1937 Anderson et al 208-23 DANIEL E. WYMAN, Primary Examiner 'P. E. KONOPKA, Assistant Examiner U.S. Cl. X.R. 

